Ten Fascinating Facts about Seahorses that I Learned from Ocean Rider

Kim Steutermann RogersThursday, October 7, 2010

On three oceanfront acres just south of Kailua-Kona airport on Hawaii (Big) Island, an unusual fish farm quietly operates. For 13 years, Ocean Rider has bred and raised seahorses. That’s right, seahorses. They really do exist.

The mission of Ocean Rider is to eliminate the take of wild seahorses around the world by providing aquarium users with pairs of domesticated, hand-raised seahorses. Their business start was the result of a conservation desire—to save the seahorse in the wild. Ocean Rider does not discharge seawater into the ocean. They do not sell seahorses to residents of Hawaii. They do not sell to aquarium stores. They do expend a great deal of effort on education, offering one hour tours, twice a day, five days a week.

1. Seahorses are actually fish. So, their offspring are called fry. They have pectoral fins and dorsal fins, gills and the same bones as a barracuda or tuna. It’s just that the seahorse’s fins, gills and bones are found in different places and used in very different ways.

2. Take the tail. It’s prehensile. Meaning it can wrap around any object in the seahorse’s environment—like coral—or even another seahorse. (More on that later. Warning: It’s R-rated.) A seahorse on the run may wrap its tail around coral, say, and change its body color to camouflage itself from a predator. And it can do so—going from black to neon green to orange—in just a couple seconds.

3. Seahorses range in size from one-half inch to 14 inches in length.

4. Seahorses are found in tropical and temperate waters around the world, including two different species in Hawaii. Although a seahorse sighting in the wild is rare here in Hawaii, one species lives on the reef and the other is found at depths up to 1,000 feet. (Ocean Rider raises both of these species for viewing and conservation purposes only.)

5. Seahorses have rods and cones in their eyes just like humans. So, they can see in color. They can also focus on objects up to 15 feet away. Stick your face up to the water to view these guys in a tank found at Ocean Rider, and they can see the very smiles on your faces.

6. Seahorses aren’t exactly contenders for the Kentucky Derby. They may have dorsal fins fluttering up to 35 times per second and that move them through the water, and they have pectoral fins behind their heads to guide them, but they don’t slip through the seas with the speed and ease of a tuna.

7. But like a tuna, seahorses are predators. They eat live food. Because their jawbones are fused, they cannot chew, and so they wrap their prehensile tails around coral and suck in passing plankton and crustaceans. The deeper living species wait for night when the plankton appears, and they ascend to the nutrient-rich waters of the surface. Seahorses graze continually, because they have no place in which to store food. Their linear gastro-intestinal tract provides no sack-like stomach; a fact Ocean Rider discovered when they started their farm 13 years ago. Now, they feed their baby seahorses six to seven times a day and boosted their seahorse survival rate from 1% to 50%. In the wild, only one out of a thousand seahorses survives; the rest wind up as fish food.

8. Ocean Rider boasts that it was the world’s first seahorse farm and that they have the largest living and breeding such farm in the world. They have over 20,000 seahorses from over 20 different species, and all 20,000 have voracious appetites. Ocean Rider spends over 50% of their resources just in the cultivation of live feed. They dug a 20-foot well to reach saltwater, which mixes with fresh water that washes through lava tubes and falls directly from the sky to create an alkaline pond. Shortly thereafter, seahorses’ favorite food showed up—Hawaii’s endemic shrimp. But raising and breeding shrimp is still not enough. So, brine shrimp—a.k.a. sea monkeys—are supplemented from the Great Salt Lake. And seahorses are trained to eat the frozen shrimp that Ocean Rider’s customers—aquarium owners—will be feeding their seahorses. Seahorses, it turns out, learn by observation, so when Ocean Rider found one seahorse willing to eat frozen shrimp, they named him Mikey, of course, and moved him from tank to tank teaching other seahorses about the yummy goodness of frozen shrimp. After two years, a surprising thing happened. Ocean Rider’s seahorses started eating frozen shrimp all on their own—without, even, the tutoring of Mikey.

9. You can tell the difference between males and females by the male’s fleshy patch of skin--a pouch—in the lower abdomen. Unlike most fish, seahorses in the wild are monogamous and mate for life. Courtship involves a male and female seahorse entwining their tails and swim—belly to belly, eye to eye—up and down the water column. They both flash their colors and the male inflates his pouch with seawater. If the female is impressed enough, she will deposit her eggs in his pouch, where they get fertilized. After 30 days, the male goes into labor. The male seahorses at Ocean Rider do this by sinking down to the bottom of the tank, assuming a jackknife position and over two minutes or so pushing out as many as 600 baby seahorses. A minute later, the courtship ritual starts again, and the female deposits another batch of eggs, and the cycle starts again. Seahorses are among the only animal species on Earth in which the male bears the unborn young.

10. In the wild, seahorses live, on average, four to five years. At Ocean Rider, some of the first seahorses they sold aquarium owners 13 years ago are still alive.

And a bonus:

11. According to Ocean Rider, not too long ago, one million seahorses were captured and sold to the aquarium trade annually. Today, that number has dropped to 25,000. Ocean Rider suggests that seahorse farms like theirs are helping to reduce the take of seahorses in the wild and preserving the species. One of Ocean Rider’s primary messages to guests is conservation of all the world’s fisheries, not just the seahorse. They support “resting” some open ocean fish populations to give the youngsters a chance to grow up and replenish stock that is harvested for food. They encourage smart consumer choices—eating only sustainably caught fish. They endorse regulations to put a cap on the amount of fish that can be taken from Hawaii’s reefs each year. In the mean time, they plan to continue breeding and raising to serve as an alternative to the wild-caught seahorses for the pet trade, and should seahorses near extinction in the open ocean, to use their captive stock as a springboard for a reintroduction of the wild.